Broadcasting, (at least here) means transmission through air. So some means needs to be provided to launch our carefully constructed modulation into the air (transmission medium). There many ways to do this both by electrical and magnetic priority simulation of the ether, simple dipoles, yagi, frame box´s, cylinders, patches, horns, slots. In fact anything stuck up in the ether will couple something. (Well LED RAM memories are an exception)
The pre-runner to a YAGI. Just the simple dipole, folded dipole, short dipole, long dipole or monopole..
A rather simplistic calculation of the radiation patterns of an antenna array